ABEM Terrameter SAS 1000 / SAS 4000
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7.4
RESISTIVITY AND IP LOGGING
N. B. Resistivity or IP measurements should not be made during a SP logging run.
•
Select Up
•
Enter the actual depth in, meters, where the upwards resistivity logging should
commence.
•
Adjust the depth of the probe to the depth newly entered.
•
Press
.
All the selected “upwards” modes are now passed through one by one, followed by an
imperative to hoist the probe to next level for measurement.
•
Press
.
•
Etc.
7.5
THE RESISTIVITY AND IP MODES ARE EXPLAINED BELOW
FLUID RESISTIVITY LOGGING
The current is injected via the ring electrode, while the potential is measured between the
shoulder electrode 0 m and the chamber electrode. The fluid resistivity is calculated,
presented on the display, and saved in the SAS 1000 / 4000. In case of small-diameter wells a
correction is needed. In table 8.1 are listed the correction factors to be used. The calculation is
not done to the stored values.
SHORT NORMAL LOGGING
Current is injected via the shoulder electrode, 0 m). The corresponding response voltage is
measured between the ground potential reference and the ring electrode at the bottom of the
probe. The SAS 1000 / 4000 will display the resistivity of the surrounding medium.
LONG NORMAL LOGGING
Current is injected via cable electrode 1.2 m while the potential is measured at the ring
electrode at the bottom of the probe. The SAS 1000 / 4000 will then display the resistivity of
the surrounding medium.
Well diameter in mm. Correction
factor
50 - 60
1.08
60 - 70
1.06
80 - 90
1.03
90 - 100
1.01
Table 7-1: Correction factors used in the SAS 1000 / 4000 for small-diameter wells when
measuring fluid resistivity.
